I’ve been asked by multiple people to talk about the theoretical EM Drive, a spaceship propulsion technology that should be impossible.

There was some news about a year ago about some people who built a homemade EM drive that seemed to work, but now, it seems that NASA has taken a look at the papers produced from that experiment and they’ve decided… This is legit.

So, most rockets work on the whole, every action produces an equal and opposite reaction thing.

But an EM drive works by firing targeted microwaves into a conical structure, also called a frustum, where it bounces back and forth, combining with other waves to build in intensity and create a thrust.

But wait… How?

The microwaves don’t travel out of the engine. It all remains self-contained, so no matter how much the microwaves intensify, there’s nothing coming out to push it the other way.

The thrust is only 1.2 micronewtons per watt, which is very, very small, so small in fact that a passing gust of air could have caused it, so they did it again in a vacuum chamber, remember all of this was just built in their home.

We can't say that it works yet, all we can say is it passed peer review, which basically removes it from the list of fringe ideas. And that itself is very cool.

Now, there are 4 theories that have been put forth to explain this phenomena, and I'm just going to touch on them here because to put it plainly... I don't understand any of this.

The first one is radiation pressure.

This one says that the difference in the pressure the radiation is exerting on different areas of the cone causes something called the Lorentz Force to act on charged particles around the chamber, which creates thrust.

The next one is vacuum energy

A QVT, or quantum vacuum thruster, is a theoretical engine that uses quantum vacuum fluctuations in the zero point field as a very low-density plasma using magnetohydrodynamics.

Some also point to pilot wave theories, which is a non-mainstream interpretation of quantum mechanics, as a way to explain the engine pushing off of the quantum vacuum to create thrust.

The third is Quantized Inertia.

A physics professor named Mike McCulloch created an explanation that he calls quantization of inertia.

This relies on a theoretical type of energy predicted by general relativity called Unruh Radiation, which an accelerating object experiences as black body radiation.

And at very low acceleration, the wavelength of Unruh Radiation can become so large it can't fit in the observable universe. And so then it becomes quantized.

The problem is, this assumes that Unruh Radiation is real, but it's never been proven, and it would also require the speed of light inside the cavity to change, which is also not supposed to happen...

But as crazy as this one sounds, it's apparently testable, so there are some experiments in the works on that.

And last but not least is photon leakage.

And this one... I might actually understand.

This relies on wave-particle duality of the photons that as they collide in the chamber, their waveforms engage in destructive interference, which cancels out their electromagnetic energy, but allows the photons to pass through the chamber wall, thus emitting a tiny amount of energy and creating thrust.

"Some say God is living there [in space]. I was looking around very attentively, but I did not see anyone there. I did not detect either angels or gods....I don't believe in God. I believe in man - his strength, his possibilities, his reason."Gherman Titov, Soviet cosmonaut, in The Seattle Daily Ti